Cold Air Intake woes...

Avar928

Well-Known Member
First Name
Michael
Joined
Dec 25, 2018
Messages
316
Reaction score
267
Location
DMV
Vehicle(s)
2018 JLU 2.0 Sport S Granite
So I just installed the Mishimoto CAI on my Sport S and really love it up until about 75mph. Sounds beautiful and feels like she pulls better along with the IC pipe and GFB DV+ I put on earlier this year. However, after 75 but more approaching and after 80 my Jeep struggles. I feel I have to floor it just to get anything. With stock it was surprisingly easy to get up to triple digits, shocked me a few times but now it's a struggle to keep up with traffic in the area or pass cars let alone big rigs (highway speed limit 55, realistic flow speed 70-75, passing speed 80+).

The wrangler is going half country soon again and I'm contemplating going back to stock for the intake and selling my basically brand new CAI (with cleaner) if anyone is interested.

Anyone have these issues? Great pull and response mid range but after that, basically feels dead.
Advertisement

 

Rub-ISH

Well-Known Member
Joined
Jul 25, 2019
Messages
103
Reaction score
89
Location
Las Vegas
Vehicle(s)
2018 JLUR 2.0t, 2019 Volvo XC40 RDesign polestar, 2006 Audi A3
Are you sure you dont have a boost leak? I have the same setup...ended up swapping back to the stock dv
 
OP
OP
Avar928

Avar928

Well-Known Member
First Name
Michael
Joined
Dec 25, 2018
Messages
316
Reaction score
267
Location
DMV
Vehicle(s)
2018 JLU 2.0 Sport S Granite
Doubtful but I'll check. I've been running the Mishimoto IC pipe and DV+ for months and it's been great.

Only when I installed the CAI yesterday am I having issues. I guess more airflow can exacerbate a leak but again, I would think I would be bogged down pre-CAI.
 

Rub-ISH

Well-Known Member
Joined
Jul 25, 2019
Messages
103
Reaction score
89
Location
Las Vegas
Vehicle(s)
2018 JLUR 2.0t, 2019 Volvo XC40 RDesign polestar, 2006 Audi A3
Doubtful but I'll check. I've been running the Mishimoto IC pipe and DV+ for months and it's been great.

Only when I installed the CAI yesterday am I having issues.

I did the same thing...HAd the IC pipe and the DV+ for a couple of months with no problem...Then added the intake when it was released. At that point I immediately noticed a difference, and heard an audible honking ( like a goose) when the DV+ released. Drove it for a few days like that only to discover the rear silicone coupler on the IC pipe had blown off ever so slightly. The hose clamp was crooked when I found it.

I fixed that issue and the honk died down...eventually it happened again, the performance fell flat at certain rmps. I did a lot of trouble shooting even with GFB involved and I basically came to the assumption that the valve was closing to suddenly and causing a pressure back up because the Diverter pathway back to the turbo is so restrictive. The combination of the added volume from the CAI and the quick snapping shut of the valve repeatedly blew that rear coupler off.

Eventually I put better clamps on but I still found it to perform better with the stock DV...(never did try and run it without the secondary spring)

Probably not your issue but that is what has worked for me
 
OP
OP
Avar928

Avar928

Well-Known Member
First Name
Michael
Joined
Dec 25, 2018
Messages
316
Reaction score
267
Location
DMV
Vehicle(s)
2018 JLU 2.0 Sport S Granite
I did the same thing...HAd the IC pipe and the DV+ for a couple of months with no problem...Then added the intake when it was released. At that point I immediately noticed a difference, and heard an audible honking ( like a goose) when the DV+ released. Drove it for a few days like that only to discover the rear silicone coupler on the IC pipe had blown off ever so slightly. The hose clamp was crooked when I found it.

I fixed that issue and the honk died down...eventually it happened again, the performance fell flat at certain rmps. I did a lot of trouble shooting even with GFB involved and I basically came to the assumption that the valve was closing to suddenly and causing a pressure back up because the Diverter pathway back to the turbo is so restrictive. The combination of the added volume from the CAI and the quick snapping shut of the valve repeatedly blew that rear coupler off.

Eventually I put better clamps on but I still found it to perform better with the stock DV...(never did try and run it without the secondary spring)

Probably not your issue but that is what has worked for me
That gives me a source to check.. Unfortunately I can't go back to the stock diverter without having to actually purchase a new diverter.
 

Rub-ISH

Well-Known Member
Joined
Jul 25, 2019
Messages
103
Reaction score
89
Location
Las Vegas
Vehicle(s)
2018 JLUR 2.0t, 2019 Volvo XC40 RDesign polestar, 2006 Audi A3
That gives me a source to check.. Unfortunately I can't go back to the stock diverter without having to actually purchase a new diverter.
Had to do the same... You could try and remove the larger spring from the DV+

but here is the link to the mopar store I picked a second valve up from

Stock DV
 
OP
OP
Avar928

Avar928

Well-Known Member
First Name
Michael
Joined
Dec 25, 2018
Messages
316
Reaction score
267
Location
DMV
Vehicle(s)
2018 JLU 2.0 Sport S Granite
I may tinker with it when not traveling. Otherwise for now, back to stock :(
 
OP
OP
Avar928

Avar928

Well-Known Member
First Name
Michael
Joined
Dec 25, 2018
Messages
316
Reaction score
267
Location
DMV
Vehicle(s)
2018 JLU 2.0 Sport S Granite
Swapped back to stock and went for a brisk run on the highway, there's a long on-ramp that you need to get up to speed on the straight to catch up to traffic. Pinned it to the CAI being the problem....power at the higher end was back to normal as well as response. Lower end felt normal, I felt it was snappier with the CAI. Oh well. I did check for leaks, none. Couplers were all seated at the IC pipe, clamps tight. No air or bubbles I took note of.

@Mishimoto Any ideas? Unfortunately it's used, albeit 24hrs, so I can't even return it.
 

Crusifix

Well-Known Member
First Name
Jeff
Joined
Mar 8, 2019
Messages
658
Reaction score
1,176
Location
West Virginia
Vehicle(s)
2019 JLU Rubicon 2.0T Hurricane
OP
OP
Avar928

Avar928

Well-Known Member
First Name
Michael
Joined
Dec 25, 2018
Messages
316
Reaction score
267
Location
DMV
Vehicle(s)
2018 JLU 2.0 Sport S Granite
Are their hose clamps the T-clamp style or Worm gear clamps? I have found over the years that I can almost always count on a leak with the T-clamp style. I've ran systems pushing 40+psi. Nothing works better than the worm gear clamp for equal pressure on the couple. I only like the T-bolt clamps when it is metal to metal couples.

Turbosmart has some of the best imo.
https://www.summitracing.com/search?SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=turbosmart clamps
Worm gear clamps on the intake and IC pipe.
 
OP
OP
Avar928

Avar928

Well-Known Member
First Name
Michael
Joined
Dec 25, 2018
Messages
316
Reaction score
267
Location
DMV
Vehicle(s)
2018 JLU 2.0 Sport S Granite
I may try taking the spring out and seeing how that affects performance, maybe upgrade the clamps. If there's no change I'll regrettably be selling a pretty much new Mishimoto CAI with a reoiling kit.
 

Rub-ISH

Well-Known Member
Joined
Jul 25, 2019
Messages
103
Reaction score
89
Location
Las Vegas
Vehicle(s)
2018 JLUR 2.0t, 2019 Volvo XC40 RDesign polestar, 2006 Audi A3
Remember the positive effects of the intake are actively being combated by the ECU!

Without a tune, which are currently lacking, the ECU is trying to keep fuel trims and airflow ratio within the stock limits.

I.E. there are limited quantifiable benefits to running the CAI...HP gains wont really happen, efficiency in airflow is about it for now
 
OP
OP
Avar928

Avar928

Well-Known Member
First Name
Michael
Joined
Dec 25, 2018
Messages
316
Reaction score
267
Location
DMV
Vehicle(s)
2018 JLU 2.0 Sport S Granite
Remember the positive effects of the intake are actively being combated by the ECU!

Without a tune, which are currently lacking, the ECU is trying to keep fuel trims and airflow ratio within the stock limits.

I.E. there are limited quantifiable benefits to running the CAI...HP gains wont really happen, efficiency in airflow is about it for now
Oh, I know. I just didn't expect performance to be cut though which is my biggest gripe right now and why I returned the CAI to stock.

My Jeep is on loan right now going multi-state so it'll be a while before I get her back to toy with, which is why I needed reliable predictable performance at higher speeds for highway stretches where 80+ is the flow. I can't have them flooring it and her struggling to keep up when I drove cross country and back stock and didn't have that problem.

So it's not a question of seeing gains but rather I'm not even reaching baseline :(
 

funglenn

Well-Known Member
First Name
Glenn
Joined
Jun 14, 2020
Messages
67
Reaction score
9
Location
Maryland
Vehicle(s)
2020 JLUS North Edition
Remember the positive effects of the intake are actively being combated by the ECU!

Without a tune, which are currently lacking, the ECU is trying to keep fuel trims and airflow ratio within the stock limits.

I.E. there are limited quantifiable benefits to running the CAI...HP gains wont really happen, efficiency in airflow is about it for now
there is one tune out that I have not tried yet, but did try their stuff on my BMW and it was amazing. Burger Tuning has a tune for our engines. It is a vampire setup but people on the forum say it is worth it. I can definitely recommend Terry at BM and their work--they specialize in turbo setups. He also does custom stuff if you work with him--there def is a need....
 

Mishimoto

Well-Known Member
Rock Sponsor (Level 1)
First Name
Mishi
Joined
Jul 5, 2018
Messages
357
Reaction score
419
Location
Wilmington, DE
Vehicle(s)
Jeep Wrangler JL
I may try taking the spring out and seeing how that affects performance, maybe upgrade the clamps. If there's no change I'll regrettably be selling a pretty much new Mishimoto CAI with a reoiling kit.
Hey Michael,

This is odd and something I haven't heard of before. We ran all of our parts on our JL for several months and did a lot of highway driving and didn't have an issue. Do you know about what RPM you're running at when you feel like you're losing power?

To confirm that it is definitely the intake causing the issue, would you be willing to reinstall our intake and perform the same run? If there's any way you can log commanded vs actual boost, that would be super helpful too (not sure if that's even possible with this ECU right now).

I just went through a similar situation with my GTI (which uses a very similar turbo system as the JL, including the same diverter valve). Sometimes it would feel quick like it should, then sometimes in fourth gear it would fall flat on its face like it had no boost. I thought it was the DV+ I just installed, swapped back to stock DV, issue went away. As soon as I emailed GFB, the issue came back. Turns out my PCV valve was intermittently failing and causing the same symptoms as a bad DV.

All of that is to say that these engines do very strange things sometimes and it's tough to pinpoint issues. This really sounds like a high-load boost issue to me, but either way I'm happy to help any way I can.

-Steve
 
Advertisement

Hothead Headliners
 
Advertisement
Top